Treatment and Low-Density Lipoprotein Cholesterol Management in Patients Diagnosed With Clinical Atherosclerotic Cardiovascular Disease in Alberta

Abstract

Background: Low-density lipoprotein cholesterol (LDL-C) is an important indicator in the development and management of atherosclerotic cardiovascular disease (ASCVD). Herein, we describe the management of LDL-C with lipid-lowering therapy, among patients diagnosed with clinical ASCVD in Alberta, Canada.

Methods: A retrospective study was conducted by linking multiple health system databases to examine clinical characteristics, treatments, and LDL-C assessments. Patients with ASCVD were identified using a specific case definition on the basis of International Classification of Diseases, Ninth Revision, Clinical Modification/International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada codes between 2011 and 2015. LDL-C was assessed at the first measurement (index test) and second measurement (follow-up test) during the study period. LDL-C levels were evaluated on the basis of the 2016 Canadian Cardiovascular Society guideline recommendations for achieving < 2.0 mmol/L or a 50% reduction. Statin therapies were categorized as low-, moderate-, and high-intensity.

Results: Among the 281,665 individuals identified with ASCVD during the study period, 219,488 (77.9%) had an index LDL-C test, whereas 120,906 (55.1%) and 144,607 (65.9%) were prescribed lipid-lowering therapy before and after their index test, respectively. Most patients who received any lipid-lowering therapy were receiving moderate-/high-intensity statins (n = 133,029; 60.6%). Among the study cohort who had 2 LDL-C tests (n = 91,841; 32.6%), 48.5% of patients who received any lipid-lowering therapy did not achieve LDL-C levels < 2.0 at index date, whereas 36.6% did not achieve LDL-C levels < 2.0 or a 50% reduction at the follow-up test.

Conclusions: The current study revealed that only two-thirds of patients with ASCVD were receiving pharmacotherapy and of those, a significant proportion did not reach recommended LDL-C levels. A remarkable treatment gap was identified for at-risk ASCVD patients. Further implementation strategies are required to address this undermanagement.